An activation apparatus is used in motor vehicle technology in connection with the differential pawl to improve the drive characteristics of such vehicle when at least one driven wheel is slipping.
An application apparatus may be activated, for example, to prevent damage to the various components of the differential pawl, which components are often form-fitted together, and/or to the drive train, only as long as no drive wheels are slipping. For this purpose, in the prior art, it is usually specified that the differential pawl may only be activated by the application apparatus if either the vehicle is standing still, or the gas pedal or the fuel-feed is deactivated or is interrupted until the drive wheels are once again synchronized. In practice, it has been found that compliance with this requirement presents a number of problems, because in difficult driving situations, it places too much of a strain on the driver; and because from the driver's seat, i.e., without looking at the wheels, it is practically impossible to determine when synchronization of the wheels has been satisfactorily reestablished. Therefore, improper operation frequently leads to serious damage to components of the differential pawl and/or of the drive train, particularly to the drive shaft.
An apparatus for the acquisition of a slip signal is taught in German publication DE-AS 18 06 671. In this prior art, the slip signal is used as a control variable for the achievement of the synchronization of the driven wheels of a motor vehicle.